Computers, and in particular, computer software, is often updated by a user downloading a software patch from a host, such as the software provider, via a network, such as the Internet. Currently, patches are downloaded in their entirety from a single source and installed on the downloading machine to update the software to a current state. While this technique is operational it has several drawbacks.
First, the software provider that makes the patch available for download must provide a sufficient amount of egress bandwidth to allow multiple customers to download updates at the same time. For software providers with a large number of customers, such egress bandwidth may become very expensive.
Second, a customer must download the entire patch from one source prior to installing the patch and updating the software. While this may be acceptable for small sized patches, for a larger patch, the time needed to download the entire patch from one source may be unacceptable. Third, if the software provided has not made ample bandwidth available for the downloads (particularly difficult and expensive when a high-priority patch, such as a security update, is released), a customer may be temporarily prohibited from downloading the patch.
Recent advances in peer-to-peer networking have provided the ability to download different parts of a large file from a plurality of peers. For example, FIG. 1 illustrates a block diagram of a typical peer-to-peer environment for downloading a specific file. To download a specific file, a client 101 requests the specific file from a host 103. In response, the host transmits a peer list identifying a plurality of peers that make available for download different pieces of these requested files. For example, a video file may be subdivided into a plurality of pieces, those pieces divided into sub-pieces, and those sub-pieces divided into sub-sub-pieces. Each peer that has previously downloaded the video file, either from one source or from multiple other peers, may make available for download by other peers, such as the client 101, one or more of these sub-sub-pieces of the entire file. The peer list transmitted by the host 103 to the client 101 identifies each of the sub-sub-pieces of the requested specific file and an associated peer that makes available for download those sub-sub-pieces.
The client 101, upon receipt of the peer list from the host 103, picks a peer for each of the sub-sub-pieces from which it will download that sub-sub-piece. Upon identification of peers, the client 101 downloads each of the sub-sub-pieces from the selected peers until all of the sub-sub-pieces of the specific file have been downloaded. By downloading pieces from different peers, multiple downloads may be conducted simultaneously. As each sub-sub-piece is downloaded, the client 101 may decide whether or not it wants to become a peer that makes available for download that sub-sub-piece (i.e., share that sub-sub-piece). If the client decides it does want to share that sub-sub-piece, the client 101 identifies to the host 103 the sub-sub-piece that it is willing to share.
While peer-to-peer environments, such as that described with respect to FIG. 1, provide the ability for a client to download a specific file that it requests, such as a video file, there is currently no technique for the determining what files a client may need. For example, referring back to downloading software patches, prior to requesting a patch, a client must know not only what updates are available, but what updates the client needs. Still further, there is currently no security feature to protect a downloading computer from being compromised by identifying what it is sharing prior to that material being fully integrated into the downloading computer. Furthermore, no method exists by which multiple patches in a client's local cache may be prioritized by the software provider when the client needs to reclaim local cache space.
Accordingly, there is a need for a system and method that allows a client to identify needed software updates and securely download those updates utilizing a peer-to-peer environment.